Reaction For Creatinine Research Articles

Synthesis, Identification, and Study of the Antimicrobial and Antioxidant Activities of Some New 2,5-Disubstituted-1,3,4-Oxadiazole Derivatives

This study includes the synthesis of 2,5-disubstituted-1,3,4-oxadiazole 3-12 on creatinine derivatives that have antioxidant and microbial properties. The reaction of creatinine with hydrazine hydrate in absolute ethanol was successfully achieved to afford hydrazide derivatives 1,2. The desired 2,5-disubstituted-1,3,4-oxadiazoles 3-12 were obtained by the reaction of hydrazide derivatives with different aliphatic and aromatic acid derivatives in the presence of POCl3. FT-IR and 1H NMR spectroscopy were used to determine the structures of some compounds. The antioxidant activity of compounds 8, 9, 11, and 12, and the antimicrobial activity of compounds 1, 5, 11, and 12 were tested in vitro and showed good results.

Highly selective electrochemical quantitation of creatinine based on its chemical reaction with 3,5-dinitrobenzoate

A simple and reliable method for creatinine quantitation was developed for urine-based diagnosis as creatinine is an internal standard molecule for the calibration of fluctuating urinary concentration. Herein, the quantitation of creatinine in artificial urine was performed in the range of 1–30 mM, covering the normal concentration of human urine, using 3,5-dinitrobenzoate (3,5-DNB) as an electrochemical probe molecule. The chemical interference from various urinary species, including urea, uric acid, ammonia, ascorbic acid, alcohol, albumin, bilirubin, acetaminophen, and glucose, is confirmed to be significantly suppressed when the reaction of creatinine and 3,5-DNB is limited to 5 min with an increased OH– concentration. Additionally, the reliability of this method is confirmed for the use of real human urine samples by comparing the data obtained from this and with that of the conventional method.

Synthesis and Characterization of New Oxo-Aztedine ,Imidazoldine and Thiazolidine Rings on Creatinine and Evaluation of their Biological Activity

This work included preparation of new imine from the reaction of creatinine with aldehydes (4-nitrobenzaldehyde, 4- amino benzaldehyde, cinnamaldehyde) and ketone ( acetophenone ) in ethanol and thepresence of few drops glacial CH3COOH to obtain Schiff bases (1a,1b,1c,1d) Schiff bases were treatedwith monochloroacetyl chloride to produced (2a,2b,2c,2d), with glycine to synthesis (3a,3b,3c,3d) andwith 2-mercaptoacetic acid to prepare (4a,4b,4c,4d). The Prepared compounds had beenmeasured by (FTIR,and1HNMR ) spectroscopic techniques. Some of the derivatives were studied activity against antibacterial,antifungal and antioxidant.

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

Real-time liquid crystal-based creatinine sensor using a micro-patterned flexible substrate

ABSTRACT We propose a novel, simple, cost-effective sensor based on orientational transitions of nematic liquid crystals (LC) for real-time, quantitative, and sensitive detection of creatinine. A micro-well array structure on a polydimethylsiloxane (PDMS) substrate was fabricated to replace traditional copper grids stabilising a thin LC film, which contains 4-cyano-4ʹ-pentylbiphenyl (5CB) LC material and 4ʹ-hexylbiphenyl-4-carboxylic acid (HBA). The principle of the sensor is based on the ordering transition of LCs induced by enzymatic reactions of creatinine and creatinine deaminase (CD), resulting in an optical signal change. The orientational response of LCs was quantitatively monitored in the presence of different amounts of creatinine by cross-polarised optical microscopy and light transmittance measurement system in real time. Concentrations from 50 to 1100 μM of creatinine were successfully detected.

Very fast electrophoretic determination of creatinine and uric acid in human urine using a combination of two capillaries with different internal diameters

A capillary system formed by combining 25 and 100 μm id capillaries was used in the short-end injection mode to determine creatinine and uric acid in human urine. The separation was performed at an electric field intensity of 2.3 kV/cm. Creatinine was determined in a BGE with a composition of 20 mM citric acid/NaOH (pH 3.0), and uric acid was determined in 20 mM MES/NaOH (pH 6.0). Under these conditions, migration times of 12.2 s for creatinine and 8.6 s for uric acid were achieved. The LOD value is 2.4 mg/L for creatinine and 0.9 mg/L for uric acid; the RSD for the migration time varies in the range 0.7-1.1% (intra day) to 1.0-7.5% (inter day); RSDs for the peak areas equalled 3.4-4.0% (intra day) and 4.3-4.7% (inter day). The determined creatinine values in seven urine samples vary in the range 221-1394 mg/L for creatinine and 87-615 mg/L for uric acid. t-Test did not reveal any statistically significant difference between the developed CE methodologies and reference methods - Jaffé reaction for creatinine and enzymatic uricase test for uric acid.

Antioxidant, antimicrobial, and theoretical studies of the thiosemicarbazone derivative Schiff base 2-(2-imino-1-methylimidazolidin-4-ylidene)hydrazinecarbothioamide (IMHC)

BackgroundAdverse antimicrobial activities of thiosemicarbazone (TSC) and Schiff base derivatives have widely been studied by using different kinds of microbes, in addition different methods were used to assay the antioxidant activities using DPPH, peroxids, or ntrosyl methods. However, there are no studies describing the synthesis of TSC derived from creatinine.ResultsIn this study, 2-(2-imino-1-methylimidazolidin-4-ylidene)hydrazinecarbothioamide (IMHC) was synthesized by the reaction of creatinine with thiosemicarbazide. The novel molecule was characterized by FT-IR, UV-VIS, and NMR spectra in addition of the elemental analysis. The free radical scavenging ability of the IMHC was determined by it interaction with the stable-free radical 2,2"-diphenyl-1-picrylhydrazyl (or nitric oxide or hydrogen peroxide) and showed encouraging antioxidant activities. Density functional theory calculations of the IMHC performed using molecular structures with optimized geometries. Molecular orbital calculations provide a detailed description of the orbitals, including spatial characteristics, nodal patterns, and the contributions of individual atoms. Highest occupied molecular orbital-lowest unoccupied molecular orbital energies and structures are shown.ConclusionsIMHC shows considerable antibacterial and antifungal activities. The free radical scavenging activity of synthesized compound was screened for in vitro antioxidant activity.

GC–MS determination of creatinine in human biological fluids as pentafluorobenzyl derivative in clinical studies and biomonitoring: Inter-laboratory comparison in urine with Jaffé, HPLC and enzymatic assays

In consideration of its relatively constant urinary excretion rate, creatinine in urine is a useful biochemical parameter to correct the urinary excretion rate of endogenous and exogenous biomolecules. Assays based on the reaction of creatinine and picric acid first reported by Jaffé in 1886 still belong to the most frequently used laboratory approaches for creatinine measurement in urine. Further analytical methods for creatinine include HPLC–UV, GC–MS, and LC–MS and LC–MS/MS approaches. In the present article we report on the development, validation and biomedical application of a new GC–MS method for the reliable quantitative determination of creatinine in human urine, plasma and serum. This method is based on the derivatization of creatinine (d 0-Crea) and the internal standard [ methyl-trideutero]creatinine (d 3-Crea) with pentafluorobenzyl (PFB) bromide in the biological sample directly or after dilution with phosphate buffered saline, extraction of the reaction products with toluene and quantification in 1-μl aliquots of the toluene extract by selected-ion monitoring of m/ z 112 for d 0-Crea-PFB and m/ z 115 for d 3-Crea-PFB in the electron-capture negative-ion chemical ionization mode. The limit of detection of the method is 100 amol of creatinine. In an inter-laboratory study on urine samples from 100 healthy subjects, the GC–MS method was used to test the reliability of currently used Jaffé, enzymatic and HPLC assays in clinical and occupational studies. The results of the inter-laboratory study indicate that all three tested methods allow for satisfactory quantification of creatinine in human urine. The GC–MS method is suitable for use as a reference method for urinary creatinine in humans. In serum, creatine was found to contribute to creatinine up to 20% when measured by the present GC–MS method. The application of the GC–MS method can be extended to other biological samples such as saliva.

Prime Time for Enzymatic Creatinine Methods in Pediatrics

The literature regarding the nonspecificity of applications of the Jaffe (alkaline picrate) reaction for creatinine is generally outdated. We conducted a specificity study to update the nonspecificity information for current Jaffe and enzymatic creatinine assays. Two serum pools with creatinine concentrations within the pediatric reference interval were spiked with albumin, IgG, unconjugated bilirubin, adult hemoglobin (Hb A), and fetal hemoglobin (Hb F) to produce 1 unspiked and 5 spiked samples per pool. The 35 laboratories participating in the survey used a total of 14 method-analyzer combinations. Measurements were performed in triplicate in a single run in accordance with manufacturer instructions. Absolute differences in creatinine concentration between spiked and unspiked samples were calculated per laboratory. Mixed ANOVA was used to quantify the interferent-related CV component for the Jaffe and enzymatic methods. The interference by bilirubin and Hb A on serum creatinine measurements was <10% for most of the Jaffe and enzymatic methods. Obvious interference was observed among the Jaffe methods in samples spiked with Hb F, albumin, and IgG, but not among the enzymatic methods. The within-laboratory interferent-related CVs for the Jaffe method-analyzer combinations ranged from 8.0%-27% at a creatinine concentration of 40.4 micromol/L (0.46 mg/dL) and from 5.4%-15% at 73.4 micromol/L (0.83 mg/dL). Enzymatic methods had within-laboratory interferent-related CVs of <4% at both concentrations. Albumin, IgG, and Hb F interfered with Jaffe creatinine assays, leading to inaccuracies in estimated glomerular filtration rates that are clinically important, especially in children and neonates. Because protein error and Hb F interference do not occur with any of the enzymatic methods tested, we conclude that enzymatic creatinine methods are preferred for evaluation of kidney function in pediatric cases.

Emesis Following Ingestion of Race Car Fuel in a 7-Year-Old Male

3. Many pathological conditions contribute to elevated serum creatinine.1 Examples of pre-renal etiologies include volume depletion, massive hemorrhage, or systolic heart failure. Intrinsic renal diseases to consider include post-streptococcal glomerulonephritis, hemolytic uremic syndrome, and medication-induced interstitial nephritis or tubular necrosis. Post-renal etiologies, such as vesicoureteral reflux and kidney stones, should also be considered. Long-standing hypertension and diabetes mellitus are common etiologies of chronic renal failure, although these are unlikely causes in a pediatric patient. 4. Most likely diagnosis: False-positive creatinine value. Further investigation revealed that the race car fuel contained nitromethane. This product is reported to interfere with the Jaffe reaction for creatinine.

A Novel Proton Transfer Compound Containing 2, 6‐Pyridinedicarboxylic Acid and Creatinine and its Zinc(II) Complex — Synthesis, Characterization, Crystal Structure, and Solution Studies

AbstractThe 1:1 proton transfer compound LH2, (creatH)+ (pydcH)−, has been prepared from the reaction of creatinine, creat, and dipicolinic acid, pydcH2, (2, 6‐ pyridinedicarboxylic acid) and characterized using IR, 1H and 13C NMR spectroscopy. The first coordination complex (creatH)[Zn(pydc)(pydcH)]·4H2O, was prepared using LH2 and zinc(II) nitrate, and characterized using IR, 1H and 13C NMR spectroscopy and single crystal X‐ray crystallography. The crystal system is triclinic with space group ${\rm P}_{\bar 1}$ with two molecules per unit cell. The unit cell dimensions are a = 8.085(2) Å, b = 10.802(4) Å, c = 13.632(4) Å, α = 104.98(2)°, β = 90.31(2)° and γ = 92.55(3)°. The structure has been refined to a final value for the crystallographic R factor of 0.0381 based on 3003 reflections. The zinc atom is six‐coordinated with a distorted octahedral geometry. The (pydc)2− and (pydcH)− units are almost perpendicular to each other. Extensive hydrogen bondings between carboxylate groups, (creatH)+ and water molecules throughout the zinc(II) complex as well as π–π stacking and ion pairing play important roles in stabilizing the corresponding lattices. The protonation constants of the building blocks of the pydcH2‐creat adduct, the equilibrium constants for the reaction of (pydc)2− with creat and the stoichiometry and stability of the ZnII complex with LH2 in aqueous solution were accomplished by potentiometric pH titration. The solution studies support a self‐associated (creatH)+(pydcH)− as the most abundant species at pH = 3.4. The stoichiometry of the crystalline complex (i.e. (creatH) [Zn(pydc)(pydcH)])and that of the most abundant species detected in solution were found the same.

Comparison of electrochemical, electrophoretic and spectrophotometric methods for creatinine determination in biological fluids

Quantitation of creatinine in biological fluids was achieved using both a biosensor based electrochemical flow cell and a micellar electrokinetic chromatography (MEKC) separation method. The results obtained from each method were compared with the widely recognised clinical method based on the Jaffé reaction. This is a standard spectrophotometric assay based on the Jaffé reaction of creatinine with alkaline picrate. The biosensor for creatinine was constructed by co-immobilising the enzymes creatininase, creatinase and sarcosine oxidase (SO) using a bovine serum albumin (BSA)–glutaraldehyde (GA) procedure at a platinum electrode. Detection of the hydrogen peroxide product of the third enzyme-catalysed reaction (SO) allowed the measurement of creatinine at +0.7 V versus Ag/AgCl. The biosensor was incorporated into a flow cell arrangement which allowed rapid determination of creatinine concentrations in urine samples with a limit of detection of 4.5 μM, a response time of 1 min, a linear range of 0–500 μM and a precision of 1.14% ( n=10). The results for five urine samples were compared with the Jaffé reaction method and based on this number of samples results from the spectrophotometric method were 36.7% higher than those determined using the flow cell method. A MEKC method for creatinine determination in serum samples was also developed and employed for serum analysis, with only a simple filtration step as sample preparation. The method showed a limit of detection of 11.5 μM, a linear range of 0–4.4 mM and a peak area precision of 2.7% ( n=10). The method was applied to creatinine determination in serum samples ( n=13) from patients undergoing renal dialysis and the results compared to the Jaffé reaction procedure. The Jaffé method generated values on average 26.7% greater than the corresponding MEKC results.

Creatol, an oxidative product of creatinine in hemodialysis patients

Creatol (CTL) is a product resulting from the reaction of creatinine (Cr) with the hydroxyl radical and is identified as a precursor of methylguanidine (MG), a uremic toxin. In this study, we investigated serum CTL levels together with those of Cr and MG in 66 patients who were on maintenance hemodialysis (HD). Prior to dialysis, the mean serum levels of Cr, CTL and MG were 967 (=11.1 mg/dl) ±267 μM, 11.1 ± 4.8μM and 5.8±2.9 μM, respectively. The mean CTL level was about 1.1% that of Cr, and the CTL plus MG level was about 1.4% that of the Cr level. The reduction rates of Cr, CTL and MG by a single HD were 62.6±6.1%, 71.0±10.3% and 51.9±11.6%, respectively. The CTL level at 0.5, 1 and 6h after HD increased rapidly by 20.7±8.7%, 31.7±14.7% and 80.1±27.3%, respectively. There was a significant correlation between CTL or CTL/Cr and parathyroid hormone in patients who had just undergone parathyroidectomy. No significant correlation was found between CTL or CTL/Cr and those factors which seems to be related to the predialysis levels of reactive oxygen. Therefore, because of the good clearance of CTL and its rapid conversion to MG, its usefulness for the estimation of hydroxyl radical generation in HD patients is limited.

The role of protein kinase C in the increased generation in isolated rat hepatocytes of the hydroxyl radical by puromycin aminonucleoside

Puromycin aminonucleoside (PAN) has been known to induce proteinuria. The increased generation of reactive oxygen species (ROS) has been implicated in this toxicity of PAN. We have reported that PAN increases the synthesis of methylguanidine (MG) and creatol which are the products of the reaction of creatinine and the hydroxyl radical in isolated rat hepatocytes. However, the mechanism for the increased ROS induced by PAN is still unclear. In this paper, we investigate the role of protein kinase C (PKC) on the PAN induced reactive oxygen generation in isolated rat hepatocytes. Isolated hepatocytes were incubated in Krebs-Henseleit bicarbonate buffer containing 3% BSA, 16.6 mM creatinine and tested reagents. MG and creatol were determined by high-performance liquid chromatography using 9,10-phenanthrenequinone for the post-labeling. PAN increased MG and creatol synthesis in isolated rat hepatocytes by 60%. 1-(5-Isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), a PKC inhibitor, at 10 and 100 μM significantly inhibited MG and creatol synthesis with or without PAN. The inhibition rate is dose dependent from 10 to 100 μM. H1004, a reagent used as control for H-7, did not affect (at 10 μM) or increased little (at 100 μM) the synthesis of MG and creatol. Ro31-8425, a potent PKC inhibitor, significantly inhibited (at 10 μM) MG synthesis in the presence of PAN. PKC in the membrane fraction, a marker of PKC activation, increased over the initial concentration by a factor of 1.65-fold at 60 min incubation and 2.16-fold at 120 min with PAN, while it changed little without PAN. These results indicate that PAN activates PKC resulting in increased hydroxyl radical generation in isolated rat hepatocytes.

Study of Creatinine and its 5-Alkoxy Analogs: Structure and Conformational Studies in the Solid and Solution States by X-Ray Crystallography, NMR, UV and Mass Spectrometry

Creatinine (2-amino-1,5- dihydro-1-methyl-4-imidazolone) is a natural by-product of cellular metabolism related to muscular mass. It is excreted in human urine and is necessary for normal kidney function. Urinary secretion of creatinine serves as a bench mark for several clinical measurements. Recently, in our laboratories, during the course of an investigation of the urine of cancer patients for tumor markers, we found some new metabolites of creatinine. These were identified as 5-methoxy and 5-ethoxy creatinine by UV, NMR and Mass spectrometry and their tautomeric structures confirmed by crystal structural investigations of the metabolites. The x-ray crystallographic analysis confirmed the structures of the compound and showed that it exists in the 2-amino form. The spectral characteristics of these new compounds and the generality of the reaction are discussed in this paper. Creatinine, when allowed to react with methanol, ethanol and propanol respectively, in the presence of charcoal and air gave the 5-methoxy, 5-ethoxy and 5-propoxy creatinine derivatives respectively, suggesting a generality of a reaction. The reaction of creatinine with alcohols in the presence of charcoal and air takes place through a free radical reaction mechanism. ‡ Present Address: Analytical and Process Chemistry, MS-301, West Valley Nuclear Services Co., Inc., P.O. Box 191, West Valley, New York 14171-0191. ** Deceased

Spectrophotometric simultaneous determination of creatinine and creatine by flow injection with reagent injection

The reactions of creatinine with picric acid and of creatine with 1-naphthol and biacetyl, both in an alkaline medium, have been used to develop a flow injection method for the simultaneous determination of creatinine and creatine, respectively. The sample containing both analytes is continuously merged with a picrate stream and mixed through the reactors; the coloured stream passes through a flow cell in a spectrophotometer set at 520 nm, recording a continuous signal proportional to the creatinine concentration. The mixture of the reagents 1-naphthol and biacetyl is inserted into the stream by use of the injection valve, which results in a peak (superimposed on the continuous signal), proportional to the creatine concentration. Linear calibration graphs for both analytes were obtained up to 30 mg l−1 with relative standard deviations <2%, and a sampling rate of 42 measurements h−1. The method was applied to the determination of creatinine and creatine in broth cube samples.

A Simplified Procedure for Eliminating the Negative Interference of Bilirubin in the Jaffé Reaction for Creatinine

The negative interference by bilirubin in the measurement of creatinine by the Jaffé procedure is well documented. We describe a procedure for the elimination of interfering bilirubin by oxidation to biliverdin through the addition of potassium ferricyanide before the alkaline picrate reagent. We detected no negative interference with the addition of as much as 600 mumol/L bilirubin. The procedure shows good agreement with a recently described blank rate method for analyzing icteric samples.

Characterization of aminoalkylimidazol-4-one mutagens from liquid-reflux models

A new class of low molecular weight, aminomethylimidazol-4-one (IQ-“like”) mutagens have been produced by the reaction of creatinine with the amino acid l-threonine, in liquid-reflux models, mimicking cooking, of diethylene glycol:5% distilled water (2 h at 150°C). Two mutagens, 2-amino-1-methyl-5-propylideneimidazol-4-one (AMPI) and 2-amino-5-ethylidene-1-methylimidazol-4-one (AEMI) were isolated and characterized by UV absorption spectra, mass spectra, and 1H-NMR. The mutagen AEMI was identical to that obtained from the reaction of creatinine with acetaldehyde. These mutagens were positive in all IQ-sensitive Ames tester strains and were not inactivated by acidic nitrosation at pH 1.0. Products displaying mutagenicity were also obtained by refluxing creatinine with other hydroxyamino acids such as l-serine, l-homoserine, and l-4-amino-3-hydroxybutyric acid, and aldehydes such as glyoxal, methylglyoxal, glycolaldehyde, but not formaldehyde. Simple model systems such as creatinine and acetaldehyde may be useful in more clearly defining the exact mechanism of formation of IQ-type mutagens (aminomethylimidazo-quinolines and -quinoxalines) produced during cooking, as well as in screening for potential inhibitors of IQ-type mutagen formation, and elucidating the mechanism of such inhibition.

Jaffes' reaction for creatinine: kinetic study and spectrophotometric characteristics of the product of the reactions of creatinine, acetoacetate and creatinine and acetoacetate with alkaline picrate

Jaffes' reaction for creatinine: kinetic study and spectrophotometric characteristics of the product of the reactions of creatinine, acetoacetate and creatinine and acetoacetate with alkaline picrate

Jaffes' reaction for creatinine: spectrophotometric and kinetic study of bilirubin in the reaction

Jaffes' reaction for creatinine: spectrophotometric and kinetic study of bilirubin in the reaction